A television (TV) set is a device for receiving a television signal and for generating a television picture on a screen or monitor in accordance with the television signal. A television signal may comprise one or more channels. A television set can be configured by a user to select a certain channel among the channels contained in the television signal. The television set may be arranged to display the television picture of the selected channel. The television picture may be updated repeatedly, giving a viewer the impression of a moving picture. More specifically, each channel may provide a sequence or stream of frames. Each frame is a picture to be displayed on the screen for a brief period. The number of frames per second of a given channel is known as the frame rate of the channel. The frame rate may, for example, be between 15 and 30 frames per second. Each channel may contain audio content in addition to the video content represented by the frames. A television channel can thus be used to convey combined video and audio content to one or more spectators. A spectator is a person located near the television set and capable of watching and listening to the selected channel using the television set. A spectator may be referred to herein as a user. A channel may convey television content, that is, video content and possibly audio content, which may comprise various programs such as news programs, films, and transmissions of sporting events.
A television station, i.e., a television broadcaster, often plans and transmits programs on a certain channel in accordance with a time schedule. Such a schedule may be referred to as a program schedule or a broadcast schedule. A collection of program schedules of several channels may also be referred to collectively as a program schedule. A program schedule may be equivalent to or provided in the form of a list which comprises one or more and possibly very many program entries. Each program entry may comprise, for example, a name, number, or other identifier of a channel, a start time, and a description of a program scheduled to start at the start time. The description may comprise, for example, a name or title of the program or any other kind of textual or graphical information about the program. Program schedules may be communicated to television spectators to help them decide which programs they want to watch. For example, program schedules may be published in newspapers, magazines, and on the World Wide Web. Furthermore, program schedules may be included in the television signal delivered to the television set. The television set may have a user interface, e.g., a remote control, for enabling the user to display a current program schedule, or portions thereof, on the screen.
Some television sets are equipped with an electronic program guide (EPG) unit. An EPG unit may be designed to provide a user with program schedule information. The program schedule information provided by the EPG unit may be configurable by the user. The user may thus be enabled, for example, to schedule upcoming programs that he/she wants to watch or which should be recorded automatically by the television set. For instance, the television set may be configured to tune automatically to a channel at a certain time in accordance with the program schedule information provided by the electronic program guide unit. For example, the television set may thus tune to channel number 1 at 9 p.m. on a certain day assuming that the program schedule information comprises an entry indicating channel 1, 9 p.m., and the respective date. An electronic program guide unit may also be designed to enable the user to display program schedules, or parts thereof, e.g., in accordance with configurable filters or sorting criteria. The program schedule information provided by an electronic program guide unit may be updated, e.g., automatically on the basis of program schedule information encoded in the television signal, for example.
In addition, broadcasters often include program announcements in their television broadcasts to announce programs scheduled to be broadcast in the near future, e.g., within the next 14 days or so. Such announcements are also known as TV promotions. They often include a title of the upcoming program as well as a date and a time of day. This information, e.g., the title, the date, and the time of day, is usually displayed on the screen for a few seconds. A user who wants to remember this information may note it down using paper and pen, or program it into the electronic program guide unit, assuming that the EPG unit allows the user to do so. Both methods can, however, be cumbersome. Notably, when a television station announces a program, it can be difficult for the user to open a menu of the EPG unit and to navigate to a time slot corresponding to the announced program.
Interactive television (ITV) technology enables a television provider, e.g., a cable company, a satellite provider, or a television broadcast station, to complement TV promotions with additional information delivered via a separate data channel in the television signal. The television set may thus reserve announced programs automatically in the EPG unit. This, however, requires the television set to know the protocol of the ITV provider. Today, ITV is still an expensive solution, some of its features are provider-specific, and it fails if the program announcement is not transmitted via the separate data channel.